Brain-damaged patients who appear to have lost signs of conscious awareness might still be able to create new memories — showing signs of new neural networks and potential for partial recovery, a new study shows.

In patients who have survived severe brain damage, judging the level of actual awareness has proved a difficult process. And the prognosis can sometimes mean the difference between life and death.

According to a Scientific American report, new research suggests that some vegetative patients are capable of simple learning — a sign of consciousness in many who had failed other traditional cognitive tests. The findings are presented in a paper today in Nature Neuroscience. Mariano Sigman, senior study author and director of the Integrative Neuroscience Laboratory at the University of Buenos Aires, said researchers wanted to “have an objective way of knowing whether the other person has consciousness or not.”

The neuroimaging work had surprised doctors by showing that some vegetative patients, when asked to imagine performing physical tasks such as playing tennis, still had activity in premotor areas.

In other patients, verbal cues sparked language sectors. Recent research has revealed that about 40 percent of vegetative state diagnoses is incorrect — which could have an impact on cases such as the painful starvation and dehydration death of Terri Schiavo.
[26Sept09, Washington, DC, www.LifeNews.com, #4715]